Fig. 3

Adapted schematic illustration of Stamm’s AUS effects for NMR chemical shifts [24]. \({\varvec{\delta}}_{{\varvec{A}}}\) and \({\varvec{\delta}}_{{\varvec{C}}}\) are the chemical shifts of non-complexed acceptor protons and acceptor protons in complexes. \({\varvec{\delta}}_{{{\varvec{A}}\left( {{\varvec{AUS}}} \right)}}\) and \({\varvec{\delta}}_{{{\varvec{C}}\left( {{\varvec{AUS}}} \right)}}\) are the chemical shifts affected by AUS effects